Solid-liquid equilibrium and hydrogen solubility of trans-decahydronaphthalene plus naphthalene and cis-decahydronaphthalene plus naphthalene for a new hydrogen storage medium in fuel cell system

Solid-liquid equilibrium was measured for benzene+cyclohexane, traiis-decahydronaphthalene+naphthalene and cis-decahydronaphthalene+naphthalene under the atmospheric pressure in the temperature range from 226.69 to 353.14K. The apparatus was specially designed in this study. and it was based on a cooling method. The phase diagram with the complete immiscible solids was observed for the three systems, and the eutectic point was found at x(2) = 0.2709 and T-eu = 232.11 K for benzene + cyclohexane, x(2) = 0.9816 and T-eu = 241.98 K for trans-decahydronaphthalene + naphthalene, and x(3) = 0.9822 and T-eu = 225.74 K for cis-decahydronaphthalene + naphthalene, respectively. Hydrogen solubility was also measured for the two pure substances, trans-decahydronaphthalene and cis-decahydronaphthalene, and the three mixtures, trans-decahydronaphthalene + cis-decahydronaphthalene, trans-decahydronaphthalene+naphthalene, and cis-decahydronaphthalene+naphthalene, in the pressure range from 1.702 to 4.473MPa at 303.15K. Considering the solid-liquid equilibrium data, mole ratio of trans-decahydronaphthalene:cis-decahydronaphthalene was set to 50:50, and those of trans-decahydronaphthalene +naphthalene, and cis-decahydronaphthalene +naphthalene to 85:15. The hydrogen solubility increased linearly with the pressure following the Henry's law for all systems. The experimental solubility data were correlated or predicted with the Peng-Robinson equation of state [D.Y Peng, D.B. Robinson, Ind. Eng. Chem. Fundam. 15 (1976) 59-64; R. Stryjek, J.H. Vera, Can. J. Chem. Eng. 64 (1986) 323-333]. (c) 2007 Elsevier B.V. All rights reserved.